The purpose of this project is to determine whether the use of various types of anti-hypertensive agents in the elderly is associated with differences in side effects, risk factors, and the incidence of clinical and subclinical cardiovascular-disease (CVD) endpoints. The setting for this project is the Cardiovascular Health Study, a prospective cohort study of risk factors for stroke and coronary heart disease in persons 65 and older. In June 1990, 5201 participants completed an examination that included: questionnaires about medication use, diet, cognitive function, depression, physical function and activity; fasting and 2-hr post challenge glucose and insulin; fasting total cholesterol, HDL cholesterol, fibrinogen and others; seated, orthostatic and ankle-arm blood pressures; anthropometric measures; electrocardiography, Holter monitoring, echocardiography, and carotid ultrasonography. Follow-up procedures have included semi-annual contacts and surveillance for CVD endpoints. Cohort retention has exceeded 96% of survivors. The second examination began in June 1992, repeats the baseline measures, adds MRI head scans, and recruits 600 new minority participants. We developed new methods to assess medication use; for estimating use of beta-blockers and beta-agonists, this method, but not self-report, showed a significant effect on mean heart rate. Proposed validation efforts will use blood levels of selected medications. Complete data on medications were available for over 98% of the cohort at each annual visit; analyses of the year-one follow-up data suggest that the use of anti-hypertensive medications was stable within individuals. Using Cox proportional- hazards model and new models for longitudinal data analysis, we will assess the association between the use of various types of antihypertensive medications and side effect, CVD risk factors, intermediate outcomes, and major CVD endpoints. Key intermediate outcomes include changes in left ventricular mass, carotic atherosclerosis, ECG abnormalities, and MRI-scan results. This project will enable us to pursue vigorously a set of related analyses of the effects of anti-hypertensive medicines on a variety of outcomes in the elderly.